"An L-shaped heated bench, using the rocket mass heater clean-burning and super-efficient wood burning technology. The '6' refers to diameter of heat-exchange ducting.
This design provided the sole heat for an older Portland cottage/apartment of about 800 sf. Over 4 years, we used less than half a cord of salvaged wood per year (local arbor trimmings and building debris). We ran the fire 2 to 4 hours in ordinary cool, rainy weather, and up to 6-8 hours when the weather dropped below 20 F, for constant 24-hour warmth. In summer, the earthen bench was not heated, and instead helped keep the house cooler than it had been in previous years with no need for fans.
The document prints 3 pages at 11"x17", or 6 pages letter size. Includes photos; scale drawings of floor plan, elevation, and cross-section cutaway views; and builder's notes on the construction process.
These are as-built drawings for information only; no guarantees or licenses implied. References to ASTM standards and building codes are included to help prospective builders research local building requirements."